The present invention relates to what is called a cupped drink automatic vending machine for vending a drink such as iced coffee which is put into a cup when a predetermined coin or bill is inserted into a slit.
A conventional cupped drink automatic vending machine is provided therewithin with a cup feeder, a plurality of material feeders accommodating materials such as coffee, milk and sugar, a diluent feeder for feeding a diluent such as water and hot water, and an ice feeder for feeding ice, as described in, for example, Japanese Utility Model Laid-Open No. Sho 62-199885 (G07F13/06).
When a customer inserts a coin or a bill into a slit and a drink is selected, the vending operation is started. A cup is dropped from the cup feeder and transferred by a transferring means to the position where a material is fed. After the material is fed into the cup, the cup is next moved to the position where the dilute is fed. After the dilute is fed, the cup is moved to the position where ice is fed from the ice feeder, and ice is finally put into the cup.
The ice feeder in this type of automatic vending machine is generally composed of an auger ice making machine for producing ice chips. The ice making machine produce ice and stores a predetermined amount of ice in a storage tank. When the cup is transferred to the predetermined position at which ice is supplied during the vending operation, the door for closing the ice discharge port is held open for a predetermined time, so that ice chips are discharged and dropped into the cup through an ice chute.
However, the ice making performance of such an ice making machine is generally about 2 kg/h. If cups of drink are continuously bought, the ice making performance cannot meet the demand. Since an agitator for discharging ice is continuously driven in the storage tank of the ice making machine, when the amount of ice discharged per unit time is small, the edges of ice chips in the storage tank are rounded. In this manner, ice chips are smoothly discharged from the storage tank with a good fluidity.
On the other hand, when the amount of ice discharged per unit time is large, the angular ice chips which have been newly produced are discharged, so that the fluidity of ice chips is bad and they are difficult to discharge from the ice tank.
Consequently, in the system in which a ice discharge port is opened for a predetermined time as in the conventional ice making machine, the amount of ice put into the cup is not constant.
This condition is shown in FIG. 7. In FIG. 7, the abscissa represents the number of cups sold and the ordinate represents the amount of ice discharged from the ice making machine. On the assumption that cups of drink are continuously sold, the amount of ice discharged into each cup is plotted. The target value of the amount of ice discharged is 100 g. The symbol HL represents the allowable upper limit, LL the allowable lower limit and CA the center value of the amount of ice plotted.
As is clear from FIG. 7, in the conventional control of the amount of ice based on a predetermined hour, there is a comparatively large difference in amount of ice between sales, and it is often the case that the amount of ice discharged exceeds the allowable upper limit HL or the allowable lower limit LL. About the time when twelve cups of drink are sold, the ice making performance cannot meet the demand, so that the amount of ice stored in the storage tank reduces and, hence, the amount of ice discharged per unit time reduces. Thereafter, the amount of ice discharged decreases as a whole.
As described above, in the conventional automatic vending machine, the amount of ice discharged from the ice making machine at each sale varies comparatively large. In addition, when cups of drink are continuously sold, the amount of ice discharged begins to reduce at a comparatively early stage. As a result, a lukewarm drink (in the case of iced coffee, etc.) with too small an amount of ice, or a thin drink with too large an amount of ice is inconveniently supplied.